The atomic bombings of Hiroshima and Nagasaki were nuclear attacks near the end of World War II against the Empire of Japan by the United States at the executive order of U.S. President Harry S. Truman on August 6 and 9, 1945. After six months of intense fire-bombing of 67 other Japanese cities, the nuclear weapon "Little Boy" was dropped on the city of Hiroshima on Monday, August 6, 1945, followed on August 9 by the detonation of the "Fat Man" nuclear bomb over Nagasaki. These are to date the only attacks with nuclear weapons in the history of warfare.
The bombs killed as many as 140,000 people in Hiroshima and 80,000 in Nagasaki by the end of 1945, roughly half on the days of the bombings. Amongst these, 15 to 20% died from injuries or illness attributed to radiation poisoning. Since then, more have died from leukemia (231 observed) and solid cancers (334 observed) attributed to exposure to radiation released by the bombs. In both cities, the overwhelming majority of the dead were civilians.
